Re: [gentoo-user] kernel config for eee w/Atom N270 CPU

[Paul Hartman]

On Thu, Jun 11, 2009 at 2:56 PM, Maxim Wexler<maxim.wexler@×××××.com> wrote:
> On 6/11/09, Paul Hartman <paul.hartman+gentoo@×××××.com> wrote:
>> On Thu, Jun 11, 2009 at 1:14 PM, Maxim Wexler<maxim.wexler@×××××.com> wrote:
>>> Hi group,
>>>
>>> Been tracking down other's kern config for 900A w/ N270 Atom cpu and
>>> notice, so far, everyone goes for CONFIG_SMP=y. Why, particularly when
>>> most commenters stress keeping the kernel as slim as possible?
>>>
>>> In the <help> window we have 'If you have a system with only one CPU,
>>> like most personal computers, say N.' As far as I know the 900A has
>>> only one CPU, unless there is some sort of virtual one I haven't heard
>>> of yet.
>>
>> Does the CPU have multiple cores? If so, that's probably why.
>>
>
> hmm, when I %cat /proc/cpuinfo I get processor :0 at the top of a list
> of stuff then, just below that, processor :1 at the top of an
> identical list.
>
> Are those two cores? I think CONFIG_MCORE2=y is recommended for the
> Atom. Does MCORE2 mean 'two cores' or 'core no.2'? The <help>
> window(under Symmetric multi-processor support) says nothing about
> 'cores'  Are 'cores' and 'cpus' the same thing in this context?
>
> Well, this has taken me all morning and half the afternoon and I
> haven't even started 'Power management...' options yet. I'll just say
> 'yes' to SMP and carry on. Hopefully have the definitive answer  by
> midnight and I can make the darn kernel.

That is correct, SMP is required to use the multi-core option.
Multi-Cores and SMP are not the same thing, but are "basically" the
same thing, so the same code handles both. It appears you do have a
dual-core CPU, so you should use SMP and the multi-core option in your
kernel config. Otherwise you'll only be using half of your processor's
ability.